Originally Posted by enjenjo
It is a factory Ford motor made bt American Bosch. Outstanding system, with no new parts available. It was not common on pickups, but the bigger models, F4, F5 ect. used it a lot.
Years ago when I had a pickup with that setup.I used a rheostat type heater control under the dash between the power supply and the wiper switch set to output 6.5 volts under load.
Today, I would use a solid state voltage reducer like this VW Ignition System – Volkswagen Alternator | AppleTreeAuto.com
This is the same reducer I am running now that I show in my pics, this is not working as per my description